Yes,Both cocoa powder and chocolate chips can be added to the batter. If adding Cocoa powder, You can add 1 tbsp of Cocoa powder to the batter of 500g in weight.
For a fluffy pancake, the pancake should be closed whislt its being heated.
In order to know whether your pancake is ready to be flipped, you can check the color of the pancake. If the pancake is yellow in color in both sides, it indicates that the pancake is fully cooked. If the pancake is yellow on top and pale colored on the bottom, it is ready to be flipped.
To avoid the batter from sticking to the pan, A Non stick pan should be used and greased with butter before pouring the pancake batter on the pan
Margarine can be used instead of butter but vegetable oil is not reccomended to be used when preparing the pancake batter